Online Etymology Dictionary

tannin (n.): "tannic acid, vegetable substance capable of converting animal hide to leather," 1802, from French tannin (1798), from tan "crushed oak bark containing tannin" (see tan (v.)). Tannic acid first recorded 1836, from French acide tannique, inroduced 1834 by French chemist Théophile-Jules Pelouze (1807-1867).
tanning (n.): late 15c., "process of tanning leather," verbal noun from tan (v.). Intransitive sense "process of getting suntan" is from 1944.
tansy (n.): perennial herb native to northern Eurasia, mid-13c., from Old French tanesie (13c., Modern French tanaisie), from Vulgar Latin *tanaceta (neuter plural mistaken for fem. singular), from Late Latin tanacetum "wormwood," from shortened form of Greek athanasia "immortality," from athanatos "immortal," from a- "not," privative prefix, + thanatos "death" (see thanatology). So called probably for its persistence. English folklore associates it with pregnancy, either as an aid to contraception or to provoke miscarriage.
tantalise (v.): chiefly British English spelling of tantalize. For suffix, see -ize. Related: Tantalised; tantalising.
tantalize (v.): 1590s, with -ize + Latin Tantalus, from Greek Tantalos, king of Phrygia, son of Zeus, father of Pelops and Niobe, punished in the afterlife (for an offense variously given) by being made to stand in a river up to his chin, under branches laden with fruit, all of which withdrew from his reach whenever he tried to eat or drink. His story was known to Chaucer (c. 1369). Related: Tantalized; tantalizing; tantalizingly; tantalization.
tantalizing (adj.): mid-17c., present participle adjective from tantalize. Related: Tantalizingly.
tantalum (n.): metallic element, 1809, Modern Latin, named 1802 by its discoverer, Swedish chemist Anders Ekberg (1767-1813), for Tantalus, according to Ekberg partly because of its inability to absorb acid recalled Tantalus' punishment in the afterlife (see tantalize). Sometimes it is said to be so called from the difficulty scientists faced in obtaining a pure specimen.
Tantalus: Greek Tantalos, king of Phrygia, perhaps literally "the Bearer" or "the Sufferer," by dissimilation from *tal-talos, a reduplication of PIE root *tele- "to bear, carry, support" (see extol), in reference to his long endurance, but Watkins finds this "unlikely." Compare tantalize.
tantamount (adj.): 1640s, from verbal phrase tant amount "be equivalent" (1620s), from Anglo-French tant amunter "amount to as much" (late 13c.), from Old French tant "as much" (11c., from Latin tantus, from tam "so;" see tandem) + amonter "amount to, go up" (see amount (v.)).
tantra (n.): type of Hindu religious book, 1799, from Sanskrit tantram, literally "loom, warp," hence, figuratively, "groundwork, system, doctrine," from tan "to stretch, extend," from PIE root *ten- "to stretch, extend" (see tenet).
tantric (adj.): 1905, from tantra + -ic; used loosely in the West to denote erotic spiritualism.
tantrum (n.): 1714, tanterum, originally colloquial, of unknown origin.
Tanzania: east African nation, formed 1964 by union of Tanganyika (named for the lake, the name of which is of unknown origin) and Zanzibar. With country-name word-forming element -ia. Related: Tanzanian.
tanzanite (n.): violet-blue gemstone, 1968, named by Henry B. Platt, vice president of Tiffany & Co., because the stone was discovered in the African nation of Tanzania.
tao (n.): 1736, from Chinese tao "way, path, right way (of life), reason."
Taoism (n.): religious system founded by Lao Tzu (b. 604 B.C.E.), 1838, from Chinese tao "way, path, right way (of life), reason" + -ism.
tap (v.1): "strike lightly," c. 1200, from Old French taper "tap, rap, strike" (12c.), from a Gallo-Roman or Germanic source ultimately imitative of the sound of rapping. Meaning "to designate for some duty or for membership" is recorded from 1952, from notion of a tap on the shoulder. Related: Tapped; tapping.
tap (n.1): "stopper, faucet through which liquid can be drawn," Old English tæppa "tap, spigot," from Proto-Germanic *tappon (source also of Middle Dutch tappe, Dutch tap, Old High German zapfo, German Zapfe). Originally a tapering cylindrical peg for a cask, then a hollowed one to draw from it (compare sense evolution of spigot). Phrase on tap "ready for use, ready to be drawn and served" is recorded from late 15c. Tap-wrench, used in turning one, attested from 1815.
tap (v.2): "to supply with a tap," late Old English tæppian, from source of tap (n.1); compare German zapfen "to tap." Meaning "to draw liquor with a tap" is from mid-15c. Extended sense "make use of" is first recorded 1570s. Meaning "listen in secretly" (1869), originally was with reference to telegraph wires. Tapped out "broke" is 1940s slang, perhaps from the notion of having tapped all one's acquaintances for loans already (compare British slang on the tap "begging, making requests for loans," 1932).
tap (n.2): "light blow or stroke," mid-14c., from tap (v.1). Tap dancer first recorded 1927, from tap (n.) in the sense of "metal plate over the heel of a shoe" (1680s).
tap (n.3): "device to listen in secretly on telephone calls," 1923, from tap (v.2) in the "listen secretly" sense.
tape (n.): Old English tæppe "narrow strip of cloth used for tying, measuring, etc.," of uncertain origin; perhaps [Klein] a back-formation from Latin tapete "cloth, carpet," compare also Old Frisian tapia, Middle Low German tapen "to pull, pluck, tear." The original short vowel became long in Middle English.

Adhesive tape is from 1885; also in early use sometimes friction tape. Tape recorder "device for recording sound on magnetic tape" first attested 1932; from earlier meaning "device for recording data on ticker tape" (1892), from tape in the sense of "paper strip of a printer" (1884). Tape-record (v.) is from 1950. Tape-measure is attested from 1873; tape-delay is from 1968.
tape (v.): c. 1600, "furnish with tape," from tape (n.). Meaning "attach with adhesive tape" is from 1932; meaning "to make a tape recording" is from 1950. Related: Taped; taping.
tapenade (n.): Provençal dish made of black olives, etc., 1952, from French tapénade, from Provençal tapéno "capers."
taper (n.): Old English tapur, taper "candle, lamp-wick," not found outside English, possibly a dissimilated borrowing from Latin papyrus (see papyrus), which was used in Medieval Latin and some Romance languages for "wick of a candle" (such as Italian papijo "wick"), because these often were made from the pith of papyrus. Compare also German kerze "candle," from Old High German charza, from Latin charta, from Greek khartes "papyrus, roll made from papyrus, wick made from pith of papyrus."
taper (v.): 1580s, "shoot up like a flame or spire," via an obsolete adjective taper, from taper (n.), on the notion of the converging form of the flame of a candle. Sense of "become slender, gradually grow less in size, force, etc." first recorded c. 1600. Transitive sense from 1670s. Related: Tapered; tapering.
tapestry (n.): late 14c., tapiestre, with unetymological -t-, from Old French tapisserie "tapestry" (14c.), from tapisser "to cover with heavy fabric," from tapis "heavy fabric, carpet," from tapiz "carpet, floor covering" (12c.), from Vulgar Latin *tappetium, from Byzantine Greek tapetion, from classical Greek, diminutive of tapes (genitive tapetos) "heavy fabric, carpet, rug," from an Iranian source (compare Persian taftan "to turn, twist"), from PIE *temp- "to stretch." The figurative use is first recorded 1580s.
tapetum (n.): of the eye, 1713, from Medieval Latin tapetum, from Latin tapete, collateral form of tapes "carpet, heavy cloth with inwrought figures" (see tapestry).
tapeworm (n.): 1705, from tape (n.) + worm (n.); so called for its ribbon-like shape.
taphouse (n.): also tap-house, c. 1500, from tap (n.1) + house (n.).
tapioca (n.): 1640s, tipiaca, from Portuguese or Spanish tapioca, from Tupi (Brazil) tipioca "juice of a pressed cassava," from tipi "residue, dregs" + og, ok "to squeeze out" (from roots of the cassava plant).
tapir (n.): 1774, perhaps via French tapir (16c.), ultimately from Tupi (Brazil) tapira.
tappet (n.): machine part, 1745, apparently from tap (v.1) + -et, "but the use of the suffix is abnormal" [OED].
taproom (n.): also tap-room, 1807, from tap (n.1) + room (n.).
taproot (n.): c. 1600, from tap (n.) + root (n.).
taps (n.): U.S. military signal for lights out in soldiers' quarters (played 15 minutes after tattoo), 1824, from tap (v.), on the notion of drum taps (it originally was played on a drum, later on a bugle). As a soldier's last farewell, played over his grave, it may date to the American Civil War. The tune was revised several times in mid-19c.
tapster (n.): "person employed to tap liquors," Old English tæppestre "female tavern-keeper, hostess at an inn, woman employed to tap liquors," fem of tæppere, from tæppa "tap" (see tap (n.1)) + fem. ending -ster. The distinction of gender in the word was lost by 15c., and by 1630s re-feminized tapstress is attested.
tar (n.1): a viscous liquid, Old English teoru, teru "tar, bitumen, resin, gum," literally "the pitch of (certain kinds of) trees," from Proto-Germanic *terwo- (source also of Old Norse tjara, Old Frisian tera, Middle Dutch tar, Dutch teer, German Teer), probably a derivation of *trewo-, from PIE *derw-, variant of root *deru-, *dreu- in its sense "wood, tree" (see tree (n.)).

Tar baby "a sticky problem," also a derogatory term for "black person," is from an 1881 "Uncle Remus" story by Joel Chandler Harris. Tarheel for "North Carolina resident" first recorded 1864, probably from the gummy resin of pine woods. Tar water, an infusion of tar in cold water, was popular as a remedy from c. 1740 through late 18c.
tar (n.2): also Jack Tar, "sailor," 1670s, probably a special use of tar (n.1), which stuff was a staple for waterproofing aboard old ships (sailors also being jocularly called knights of the tarbrush); or possibly a shortened form of tarpaulin, which was recorded as a nickname for a sailor in 1640s, from the tarpaulin garments they wore.
tar (v.): late Old English, "to smear with tar," from tar (n.1). To tar and feather (1769) was famously a mob action in America in Revolutionary times (used by both sides) and several decades thereafter. The punishment itself first is found in an ordinance of Richard I (1189) as the penalty in the Crusader navy for theft. Among other applications over the years was its use in 1623 by a bishop on "a party of incontinent friars and nuns" [OED], but the verbal phrase is not attested until 18c. Related: Tarred; tarring.
tarantella (n.): 1782, "peasant dance popular in Italy," originally "hysterical malady characterized by extreme impulse to dance" (1630s), epidemic in Apulia and adjacent parts of southern Italy 15c.-17c., popularly attributed to (or believed to be a cure for) the bite of the tarantula. This is likely folk-etymology, however, and the names of the dance and the spider more probably share an origin in Taranto, the name of a city in southern Italy (see tarantula). Used from 1833 to mean the style of music that accompanies this dance, usually in 6/8 time, with whirling triplets and abrupt major-minor modulations. Related: Tarantism.
Those who were bitten generally fell into a state of melancholy, and appeared to be stupified, and scarcely in possession of their senses. This condition was, in many cases, united with so great a sensibility to music, that at the very first tones of their favourite melodies, they sprang up, shouting for joy, and danced on without intermission, until they sank to the ground exhausted and almost lifeless. [Babington's translation of J.F.C. Hecker, "The Epidemics of the Middle Ages," London, 1859]
tarantula (n.): 1560s, "wolf spider," (Lycos tarantula), from Medieval Latin tarantula, from Italian tarantola, from Taranto "Taranto," seaport city in southern Italy in the region where the spiders are frequently found, from Latin Tarentum, from Greek Taras (genitive Tarantos; perhaps from Illyrian darandos "oak"). Its bite is only slightly poisonous. Popularly applied to other great hairy spiders, especially the genus Mygale, native to the warmer regions of the Americas (first so called in 1794).
tarbrush (n.): 1711, from tar (n.1) + brush (n.1). To have a touch of the tarbrush "have a dash of African ancestry visible in the skin tone" (1796) was "a term of contempt from the West Indies" [Century Dictionary].
tardation (n.): "slowness," c. 1500, from Late Latin tardationem (nominative tardatio), noun of action from past participle stem of tardare "to slow," related to tardus "slow, sluggish" (see tardy).
tardigrade (adj.): 1620s, "slow-going, slow-moving," from French tardigrade (17c.), from Latin tardigradus "slow-paced," from tardus "slow" (see tardy) + gradi "to walk, go, step" (see grade (n.)).
tardy (adj.): 1520s, "slow," from Old French tardif "slow, late" (12c.), also the name of the snail character in the Roman de Renart, from Vulgar Latin *tardivus, from Latin tardus "slow, sluggish; late; dull, stupid," of unknown origin. Meaning "late" in English is from 1660s.
This word, not much used in English prose, is constantly employed in the U.S. and in Canada with reference to lateness in school-attendance. [Thornton, "American Glossary," 1912]
Related: Tardily; tardiness. Earlier form of the word in English was tardif, tardyve (late 15c.). Tardity "slowness of movement or action" is recorded in English from early 15c., from Old French tardete, from Latin tarditas.
tare (n.1): "kind of fodder plant, vetch," c. 1300, perhaps cognate with or from Middle Dutch tarwe "wheat," from a Germanic source perhaps related to Breton draok, Welsh drewg "darnel," Sanskrit durva "a kind of millet grass," Greek darata, daratos "bread," Lithuanian dirva "a wheat-field." Used in 2nd Wyclif version (1388) of Matt. xxiii:25 to render Greek zizania as a weed among corn (earlier darnel and cockle had been used in this place); hence figurative use for "something noxious sown among something good" (1711).
tare (n.2): "allowable difference between gross and net weight, deduction made from gross weight of goods to account for approximate weight of packaging or container holding them," late 15c., from Middle French tare "wastage in goods, deficiency, imperfection" (15c.), from Italian tara, Medieval Latin tara, from Arabic tarah, literally "thing deducted or rejected, that which is thrown away," from taraha "to reject."
targe (n.): "shield, buckler," late Old English, from Old French targe, from Frankish *targa, from Germanic (see target (n.)). Old English had a native form targe, but the soft -g- in the later word indicates it came from French.
target (n.): c. 1300, "shield," diminutive of late Old English targe, from Old French targe "light shield" (12c.), from Frankish *targa "shield," from Proto-Germanic *targ- (source also of Old High German zarga "edging, border," German zarge "border, edge, frame," Old English targe, Old Norse targa "shield, buckler"), perhaps originally "edge of a shield." Meaning "round object to be aimed at in shooting" first recorded 1757, originally in archery, perhaps suggested by the concentric circles in both. Target-practice is from 1801. Target audience is by 1951; early reference is to Cold War psychological warfare.